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Gear Review: Hydrapak SoftFlask and Giveaway!

When it comes to running, I am always looking for more water bottles. I can fill them up at home and have them ready at resupply points. For backpacking, my main water container is some sort of water bladder stored inside my pack. However, I always carry 2 plastic bottles for mixing powders. I keep these containers on the outside of my pack such that I can quickly grab some water from a stream, allowing me to walk longer. I’ve been satisfied with this approach for years, but the folks at Hydrapak are making me rethink this approach.

A few weeks ago, I received an email asking me if I wanted to check out the new SoftFlasks. At first, I was thinking, “Awesome! A new bottle for my running collection.” That is until I got the package in and my mind started wandering.

Hydrapak SoftFlask 500 mL
Hydrapak SoftFlask 500 mL

What is a SoftFlask? Well, it is a water bottle made out of thermoplastic polyurethane (TPU). This material puts the Soft in SoftFlash allowing the bottle to be collapsed to a next than nothing size when empty. Actually, when compressed it is smaller than my fist. Here are some of the high-level details.

Hydrapak SoftFlask 500 mL crushed
I crushed it

Technical Details

  • Variety of sizes 150 – 750 mL
  • High-flow silicone bite valve with twist shut-off
  • Collapsible for easy storage
  • Modular design for multi-purpose use
  • Made from soft but durable TPU
  • BPA free
  • Top rack dishwasher safe
  • Freezer safe
  • Textile carrying loop and dust cover, but can be removed to save weight

I reviewed the 500 mL option which has the following specifications.

  • 42 mm opening
  • 2 oz.

Field Test – Running

Like I said, my first thought was for use with running so that is what I tried first. I filled this bad boy (or girl) up with water and screwed the top on. Because of the molded bottom that can be used to secure it with hooks like on a backpack, the bottle will not stand. Luckily, this bottle does not leak like some other bottles I have used. The bite valve works great and has a twist type shut-off valve. I found that the twisting action can be a little tricky to use with wet hands. Typically, I need some assistance from my shirt to get a good grip. However, the flow from the valve (when opened) is outstanding.

I was a little skeptical of how comfortable this bottle would be to hold for extended time periods, but it worked well over the course of an hour. I thought it might get too floppy when it was filled with less liquid, but that was not the case. I was also very impressed with the durability. I had a few rock scrambles where I was pushing it against rocks, but I saw no signs of damage nor did the extra pressure cause the bite valve to leak. The collapsible aspect of this bottle was not necessarily needed for running, but it would come in handy if I was to store it inside a pack if I used one. As such, the bottle worked perfectly well for running.

Night Terror stepping on full Hydrapak SoftFlask 500 mL
Don’t tread on me

Field Test – Backpacking

The moment I saw how small this thing collapses I began to think about replacing my plastic bottles with it. The great thing about this is that the size (when full) is comparable to the plastic bottles I take, but when not full it can collapse to a size smaller than my fist. As such, I can put more items inside my backpack’s outer pockets for easier access. I’m all about efficiency when on the trail, and that means accessing the main compartment of my pack less often when not at camp. The durable material and leak-proof design allows me to focus on the trail instead of wondering if the thorns or rocks ahead are going to leave my pack a soaking mess. As a bonus, the 2 oz. weight is just slightly heavier than the plastic bottles I have been using.

To be fair, the bottom of the bottle has some molded features that allow it to be secured to hooks, carabiners, etc. I really do not have much use for that feature, but it could come in handy for certain backpackers. For me, I will stick to keeping it inside my backpack’s outer pockets. The bottle does come with a textile loop and a dust cover. Being the weight conscious backpacker, these items were removed immediately.


If you are a runner looking to add some new bottles to your inventory, the SoftFlasks will do the trick. However, I think backpackers will find more use from these bottles. One thing I have not tried or confirmed with this bottle is the ability to put boiling water in it. I know it can withstand hot tap water, but having the ability to put extra hot liquids in it can come in handy during winter trips.

If you would like to get one for yourself, you can buy directly from Hydrapak by CLICKING HERE.

If you are feeling lucky, be sure to enter our promotional giveaway and maybe you will win one 750 mL SoftFlask for free! Yes, that is right we are giving away the bigger brother of the product I just reviewed. Be sure to keep scrolling down to enter.


Note that I was not paid for this review and my opinions do not reflect those of Hydrapak. I did receive a the 500 mL and 750 mL versions for free for purposes of this review.


a Rafflecopter giveaway


  1. Christine Christine

    This would be a great addition to our AT Hike gear. Doing another 130 mile section in May.

    • Awesome…I hope you have a great time. I believe this bottle is coming with us during our upcoming AT section hike as well!

  2. Marisa Marisa

    This looks like a great addition to my hydration pack during long trail runs.

  3. Kel Kel

    I’d love to try this out on a long section of the AT.

  4. Eric Klein Eric Klein

    This would come in handy for my jmt hike this summer.

    • Jealous! We want to go on the JMT this summer too. Maybe another year I suppose.

  5. wil wil

    For day hikes and running.

  6. jim jim

    Prepping for some section hikes of the AT with the wife. These would make a great pack addition.

    • Glad to hear there is another backpacking couple out there. It is fantastic to be able to share your experiences with another person.

  7. Molly Molly

    I would love to win one of these and use it when I go backpacking on the AT.

  8. Jenny Jenny

    lightweight, collapsable? Why yes please, I would like one!

  9. John John

    As an AT 2000-miler (1989) and an AT volunteer Trail Maintainer, I’m alway looking for great solidly designed and built backpacking equipment.

    • Thanks for volunteering and helping keep the trail a wonderful place!

  10. John John

    I’m pleased to have served as an AT Maintainer for almost 27 years. The AT has given me more than I can ever give back to it. Hike on!

  11. I would use it while running and hiking as well, and if it really doesn’t leak, in my purse for longer trips. I always carry a water bottle around with me!

  12. John John

    Sounds great for backpacking

  13. Rick W Rick W

    This would be a great addition to my scouting, hiking, and exercise gear. Looking forward to trying it out!

  14. I am new to backpacking and am excited to learn about these!

  15. Brian Brian

    I just got a 500 ml, primarily for running. First field test will be today but looks good so far

  16. Robin Robin

    It would be part of my daypack kit.

  17. mkt42 mkt42

    Are the dust caps on these bottles tied to the bottle, or are they loose?

    They appear to pop off, rather than unscrew, which makes it easy for them to be popped off accidentally. And then the question is are they tied to the bottle, or will they fall to the ground and bounce into a crevice (which happened to me this summer while using a similar bottle).

    • They are not tied to the bottle. For what it is worth, I threw them out as I keep the bottle is my racing vest pocket away from dirt, etc.

      • mkt42 mkt42

        Thanks for the reply. I’d be using these bottles for backpacking, where they and their caps would be rolling around on the ground, so I’d want them to be protected.

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